U.S. application Ser. No. 08/510,665, now U.S. Pat. No. 5,812,983, relates to a computer software system of spread sheets and charts specialized for medical use, and more particularly, a data processing system which integrates and displays various kinds of medical data collected at irregular intervals from different sources such as doctors, nurses, laboratory personnel, and others.
The system of the '665 application is useful because tremendous amounts of data are generated in daily medical practice. Based on this data, doctors make decisions about how to treat and care for a patient. The system of the '665 application assists doctors by integrating this data and more effectively presenting it to doctors and other medical staff.
In medical practice, there are various kinds of data coming from different sources. Some of the data, for example, blood pressure, pulse rate, body temperature and urine volume, are observed by nurses several times everyday. Others like biochemical or serological tests are measured by a laboratory once a week, month, or even year. Furthermore, whether a patient is in the acute or chronic phase of an illness may affect the frequency of data collection.
Human factors exacerbate this irregularity. Sometimes a patient does not visit his or her doctor on the appointment date, and consequently, the necessary tests are not taken. There are considerable differences among doctors in the style of clinical testing and treatment of patients' problems. Clinical data may be easily missed by human error or a complicated hospital system.
In the prior art, computer systems which were developed for integration of medical information have not acquired the flexibility to fulfill the essential needs of a daily medical practice. Apart from computer systems, there have been only a few attempts to create more efficient medical information systems than the traditional handwritten medical charts or nurses' records. As explained in the '665 application, Dr. Weed of Case Western Reserve University proposed a Problem Oriented Medical Record (POMR) system in 1969. Medical Records, Medical Education, and Patient Care, Lawrence L. Weed, Press of Case Western Reserve University, 1969. According to Dr. Weed's proposal, a POMR includes a flowsheet as well as problem list, patient's database, and follow up notes. A problem list is a list of each patient's problem related to the patient's illness. A flowsheet is a list of parameters that medical personnel monitor over an extended time period for patients (e.g., blood sugar level, urine volume, etc.). A flowsheet of each problem list shows changes over time for selected clinical and therapeutic data for each patient's problem.
The CMFCS of the '665 application uses the idea of a POMR, but the CMFCS solves the problem of irregularly collected data by using real data to interpolate and fill in missing data.
Medical information almost always has several important properties such as patient identification, time, date, data field, and data itself. In the past it has been difficult to properly handle the time properties of medical information in computer systems, but relatively easy to handle other ones. As previously stated, one of the major reasons for this difficulty is the fact that most medical data is collected at irregular intervals.
In the typical clinical course, the times at which medical information is collected is irregular, thereby causing gaps in the medical data. The Computed Medical File and Chart System (CMFCS) of application No. '665 was developed to overcome the difficulties related to the gaps in medical information.
However, the CMFCS alone does not completely solve the problems related to the irregular collection of medical data. Although any time axis can be chosen for the rows of the flowsheet of the CMFCS as long as each row represents the same time interval, more than one piece of datum may exist at a single cell in a given row. For example, multiple readings of body temperature, pulse rate, or blood pressure are taken in a single day.
Because of these multiple readings, the time units associated with particular medical information may have different time axes--for example continuous monitoring, hourly, three times per day, daily, weekly, monthly, yearly or others. Therefore, a patient's medical charts should also have multiple flowsheets which correspond to the multiple time axes. These multiple flowsheets should be summarized and nested in an hierarchical order, and the CMFCS could then follow and view the clinical course of the patient's lifetime with the required detail. In prior systems, paper-based or computer-based patient record systems could not offer this kind of flexibility or detail.